1 files changed, 76 insertions, 0 deletions
diff --git a/chromium/third_party/blink/renderer/platform/fonts/font_matching_metrics.h b/chromium/third_party/blink/renderer/platform/fonts/font_matching_metrics.h
new file mode 100644
index 00000000000..c31be1c51b5
--- /dev/null
+++ b/chromium/third_party/blink/renderer/platform/fonts/font_matching_metrics.h
@@ -0,0 +1,76 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_FONTS_FONT_MATCHING_METRICS_H_
+#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_FONTS_FONT_MATCHING_METRICS_H_
+
+#include "services/metrics/public/cpp/ukm_source_id.h"
+#include "third_party/blink/renderer/platform/platform_export.h"
+#include "third_party/blink/renderer/platform/wtf/hash_set.h"
+#include "third_party/blink/renderer/platform/wtf/text/atomic_string.h"
+#include "third_party/blink/renderer/platform/wtf/text/atomic_string_hash.h"
+
+namespace ukm {
+class UkmRecorder;
+}  // namespace ukm
+
+namespace blink {
+
+// Tracks and reports UKM metrics of the number of attempted font family match
+// attempts (both successful and not successful) by the current frame.
+//
+// Only the number of successful / not successful font family match attempts are
+// reported to UKM. The class de-dupes attempts to match the same font family
+// name such that they are counted as one attempt.
+class PLATFORM_EXPORT FontMatchingMetrics {
+ public:
+  FontMatchingMetrics(bool top_level,
+                      ukm::UkmRecorder* ukm_recorder,
+                      ukm::SourceId source_id)
+      : top_level_(top_level),
+        ukm_recorder_(ukm_recorder),
+        source_id_(source_id) {}
+
+  // Called when a page attempts to match a font family, and the font family is
+  // available.
+  void ReportSuccessfulFontFamilyMatch(const AtomicString& font_family_name);
+
+  // Called when a page attempts to match a font family, and the font family is
+  // not available.
+  void ReportFailedFontFamilyMatch(const AtomicString& font_family_name);
+
+  // Called when a page attempts to match a system font family.
+  void ReportSystemFontFamily(const AtomicString& font_family_name);
+
+  // Called when a page attempts to match a web font family.
+  void ReportWebFontFamily(const AtomicString& font_family_name);
+
+  // Publishes the number of font family matches attempted (both successful and
+  // otherwise) to UKM. Called at page unload.
+  void PublishUkmMetrics();
+
+ private:
+  // Font family names successfully matched.
+  HashSet<AtomicString> successful_font_families_;
+
+  // Font family names that weren't successfully matched.
+  HashSet<AtomicString> failed_font_families_;
+
+  // System font families the page attempted to match.
+  HashSet<AtomicString> system_font_families_;
+
+  // Web font families the page attempted to match.
+  HashSet<AtomicString> web_font_families_;
+
+  // True if this FontMatchingMetrics instance is for a top-level frame, false
+  // otherwise.
+  const bool top_level_ = false;
+
+  ukm::UkmRecorder* const ukm_recorder_;
+  const ukm::SourceId source_id_;
+};
+
+}  // namespace blink
+
+#endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_FONTS_FONT_MATCHING_METRICS_H_